Sorry for basic question, but I've not done it much until now (dd hasn't had much hair!) and my first attempt was disastrous as I think I got soap in her eyes. She hates lying flat in the bath so it's no good trying to tip her back so the water doesn't run in her eyes. She will only sit upright. I tried to get my partner to shield her eyes from the jug of water which I used to rinse shampoo off but it didn't really work. Is there a knack to this?